Process and apparatus to be used in printing photographs from negatives



Aug; 11, 1931. w, MYERS 1 1,818,003

I PROCESS AND APPARATUS TO BE USED IN PRINTING PHOTOGRAPHS FROM NE GATIVES Filed Dec. 19, 1927 2 Sheets-Sheet I l p v v I NV EN TOR.

A TTOR NE Y. I

Aug. 11, 1931. J. w. MYERS 1, 0 PROCESS AND APPARATUS TO BE USED iN PRINTING PHOTOGRAPHS FROM NEGATIVES Filed Dec. 19, 1927 2 Sheets-Sheet 2 IN VEN TOR.

W BY UNITED STATES PA-rENr ;or-'r1cs 1 mm: W. MOI- JACKSON; IICBIGAI um arrmrus mo na usnn 11: Panama rao'roemns non mamas- Applleation fled December 19 1021. Serial Io. 241,081.

My invention relates to a process and a aratus to be used in printing photographs rom negatives and an object of my improve ments is to ascertain the pro er time of exposure and the pro er gr e of sensitive paper to be used an to mark the negative with the data thus ascertained so that the printing can be done correctly by a comparatively unskilled operator.

I secure this object in the apparatus shown in the .accompanyin "drawings and by the process hereinafter, escribed.-

In the accompanying drawings Figure lis'a plan view of an apparatus embodying my invention.

Figure 2 is a section on the line II, II, Fi re 1.

igure 3 is a detailed section on the line III, III, Figure 1. I

Figure 4 is a diagram illustrating the various electrical circuits.

a is an enclosed casing, or box, having a slanting top. The walls of said casing are opaque, except for the upper and greater portion of the slanting top, which consists of a glass plate I; having its surface roughened, or ground.

c is an electric lamp secured to the rear wall and within the casing a. d is a concentrating lens located above and axially in line with the lamp 0, and so constructed that the light rays received by it from said lamp shall be concentrated at ($2 at the surface of the plate b.

e represents a negative resting upon the outer surface of the plate b.

f is a tube having an opaque wall and having its ends closed. f3 is an opening through the wall of the tube f located at such a point that it shall permit the passage of the rays of light which have passed through the lens d, the plate b and the negative e. Within the tube f is a conductor 9 of a material such as selenium, the resistance of which varies with the intensity of the light that strikes upon it. The light passing through the aperture f3 falls upon the selenium conductor 9. The conductor 9 is interposed in a circuit k. in which circuit is a sensitive, ammeter 152, a switch k3, a variable resistance M and a source of current b5 the voltage of which may be regulated at will by a switch k6.

m, m2 represent electric mains, t a trans former and r a variable resistance in circuit with the lam c. I

n2 is a series of keys located adjacent to the edge of the casin a and above the left hand upper corner oft e upper surface thereof. n3 is a second series of similar keys located at the side and toward the upper left hand corner of the upper surface of said cas- 7' represents a narrow metal strip secured I to the edges of the upper surface of the casing a adjacent the series of keys n2 and n3. This strip 1s mainly spaced slightly above the upper surface of the casing so as to permit of a portion of a negative being shoved there under. The outer edges of the strip 7' extend beyond the upper surface of the casing a and I are turned downward, as shown in Figure 3,

to form a stop to limit the distance that the edge of the negative may pass under said strip. a

k is a bar having its upper end shaped to form a character, or sign, upon the negative. The bar slides vertically in ways along the side surface of the casing a and is actuated by a pivoted lever I02 and retracted by a tension spring k3. n is a bar the lower endof which is pivoted to the outer end of said lever, the upper end carrying the key 412. There is a bar In and connecting mechanism for each of the keys a2 and n3. The characters printed by actuating the keys n2 may range between the numerals 1 and 10, those;

upon the keys n3 between 1 and 4.

The operation of the above described device is as follows:

The lamp 0 is lighted from the mains, or other convenient source, and the intensity of its light is regulated by the variable resistance 1'. A part of the light from the lamp 0 passes through the glass plate b and illu-' mines the same uniformly and a part of said light passes through the lens d, is concentrated at d2 and passes through the aperture f3 falling upon the selenium conductor '9 in the tube f.

A current is passed through the circuit h by closing the switch k3 and this current is adjusted at will b varying the voltage by the switch k6, or y varying the resistance in the circuit at M for the purpose of bringing the meter to zero, density reading.

The negative is now laid upon the plate 6 and the lightest and darkest part of the image on said negative is observed and the light part is moved to the point (Z2 so that the concentrated rays from the lens at will pass through this part of the negative and strike against the selenium conductor g. The current through the circuit it will now be proportional to the light passing through this point of the negative and its intensity will be indicated by the needle of the ammeter k2, which is observed and the edge of the negative at the corner is then passed under the strip and that key 712 depressed which shall cause a bar to print the indication of the needle upon the negative.

The negative is then moved back to its position upon the surface of the plate I) and the darkest point of the image upon the negative is observed and the negative is moved until this darkest point is at (Z2 and a second reading of the ammeter is made. From this reading is subtracted the first reading-the corner of the negative is placed under the strip j adjacent to a key n3 which may show the remainder, or the proper paper, and said key is depressed to imprint its character upon the negative, as above described with reference to the keys n2.

The areas of the said points of the negative the permeability of which are determined must be very small, about the size of a pin in moving picture films and not larger than one eighth of an inch in hand camera films.

The characters upon the scale of the ammeter 772 are such as to indicate by its needle the seconds and fractions of a second that the negative should be exposed, and, or, density factors of which the exposure is a function, when the light is passing through the lightest part of the image, as above described, and the keys 122 print this time or factor upon the negative.

The grade or sensitive paper that should be used depends both upon the quantity of light passing through the lightest part of the image and the quantity of light passing through the darkest part of the image and the keys n3 are adapted to indicate this grade of paper when manipulated to correspond to a function of the quantities of light passing through both the lightest and the darkest part of the image on the negative.

\Vhat I claim is:

1. -A process to be used in printing from exposed negatives, consisting in observing the point of the image upon the negative that is most permeable to light, measuring the light-permeability of the negative at said point, and exposing the negative for a time proportional to said permeability to a grade of paper proper for said negative.

2. A process to be used in printing from exposed negatives, consisting in observing the point of the image upon the negative that is most permeable to light and the point of said image that is least permeable to light, measuring the light-permeability of the negative at each of said points and selecting the sensitive paper to correspond to a function of both of said permeabilities.

3. The combination of an enclosure having a lamp therein, said enclosure being provided with a translucent wall adapted to receive a negative laid flat thereon, said translucent wall being of such a size and so located that the negative may be moved to different positions while lying flat thereon, a concentrating lens in said enclosure adapted to concentrate light from said lamp upon a single point of said wall, corresponding in area to a limited area of the negative in the lightest or darkest part thereof, and means for measuring the intensity of the light passin from said point for the purpose describe 4. The combination of an enclosure having a lamp therein, said enclosure being provided with a translucent wall adapted to receive a negative laid flat thereon, said translucent wall being of sucha size and so located that the negative may be moved to different positions while lying fiat thereon. a concentrating lens in said enclosure adapted to concentrate light from said lamp upon a single point of said wall corresponding in area to a limited area of the negative in the lightest or darkest part thereof, and means for measuring the intensity of the light passing from said point, for the purpose described.

5. The combination of a translucent surface having light passing uniformly therethrough, a negative, said surface being adapted to receive said negative laid fiat thereon said translucent surface being of a size and so located that the negative may be moved to different positions while lying fiat thereon, and means for measuring the light-permeability of a desired part of said negative, that is of a very small area relative to the picture of said negative, said part being determined by the movement of said negative, consisting of a special intensity of light passing through one point of said surface registering with said part of said negative and means for measuring the intensity of light passing from said point.

6. The combination of a translucent wall for supporting a negative to be measured, means for directing light through a large partof said wall, means to direct a measuring light ray through a selected point of said wall, and means for measuring the degree of light of said measuring ray.

7. The process of printing a negative, the

tion.

steps consisting of directing light through a large part of the negative, selecting the int of the negative that transmits the most 0 said light, measuring the translucency of the selected point in the negative selecting the aper according to the contrast of the negative and exposing said negative for the time indicated by the most translucent point in the ne ative.

n testimony whereof, I sign this specifica- JOSEPH w. MYERS. v 

